Juice Flavors - js advanced

function solve(inputArr) {
    let juices = new Map();
    let result = new Map();
    inputArr.forEach(e => {
        let [juiceName, juiceQuantity] = e.split(' => ');
        if (!juices.has(juiceName)) {
            juices.set(juiceName, Number(juiceQuantity));
        } else {
            juices.set(juiceName, juices.get(juiceName) + Number(juiceQuantity));
        }
        if (juices.get(juiceName) >= 1000 && result.get(juiceName) == undefined) {
            result.set(juiceName, 0);
        }
        while (juices.get(juiceName) >= 1000) {
            result.set(juiceName, result.get(juiceName)+1);
            juices.set(juiceName, juices.get(juiceName) - 1000);
        }
    });

    for (const [juice,bottles] of result) {
        console.log(`${juice} => ${bottles}`);
    }

}